At an ever increasing rate, high speed and high performance transistors are more densely integrated on semiconductor dies. The amount of heat generated by the semiconductor dies increases significantly due to the growth in number of transistors per semiconductor die. If the heat generated by the semiconductor dies cannot be dissipated efficiently, the semiconductor dies may fail to operate or have a degraded operating performance. Accordingly, heat dissipation is an issue in densely integrated semiconductor dies, and efficient heat dissipation is highly desirable.
Semiconductor dies normally reside in or on a substrate and the substrate can affect the semiconductor dies performance in many ways. For instance, the heat produced by the semiconductor dies could be conducted away from their immediate vicinity through the substrate. Laminate materials are widely used in substrates, which are inexpensive and have a mature supply-base within the industry. However, the laminate materials have poor thermal properties. On the other hand, metallic and composite materials have better thermal characteristics, but they are costly and do not have sufficient resistance like the laminate materials.
To accommodate the increased heat generation of densely integrated semiconductor dies, there remains a need for improved substrate designs. The substrate design will preferably be low cost and use easily attainable materials while providing superior thermal performance.